Unwanted email is the curse of our lives. In the first quarter of 2013, spam represented 66.5% of all email traffic.

In July 2013, that rose to 71.2% – an astonishing amount of junk that chokes up our networks, takes our time in managing it and, in more serious cases, compromises our computers and our privacy.

Spam is essentially mail that is sent unsolicited and unlooked for by the recipient. Once your email address has been found by the unscrupulous senders of this rubbish, it’s likely to receive a growing amount of email as your details are shared around and added to ever more lists. Spam works because the senders of this type of communication transmit millions upon millions of emails every day. If one person in a thousand bites, then the effort is worthwhile.

So who follows up on an unwanted email? The unwary, the innocent and those who don’t understand computers may receive mails which look bona fide, click through on the link and thereby potentially expose themselves to malware, unwanted advertising, pornography and more. Of course, the recipient might actually want the product or service being advertised, but it’s unlikely to be coming from a reputable source and their consumer rights are unlikely to be protected.

Phishing emails are even worse – they lure you to an apparently genuine replica of a bank website, for instance, and get you to part with security information that allows the crooks to empty your bank account or get access to your credit card. This type of mail may come in the guise of an invitation to add a particularly attractive lady or gentleman to your social network. Or it may be a piece of sensational news, purporting to give you the inside track on a celebrity or politician’s life, affairs, death or any other aspect that might tempt you to click.

Too good to be true offers have long been used in this way – the famous Nigerian scam offers you the chance to import millions of dollars into your country and take a share in return for helping the sender (who is usually someone of high rank in their country). Many people have answered these mails, been asked to send a small donation or bank details to the scammer and then have suffered the consequences.

Mails that prey on your own insecurities or weaknesses are also rife – erectile dysfunction solved with low cost pills has long been a staple of the spammer’s portfolio.

So, how do you know when that email from your own bank arrives, whether it is spam or not? And what do you do with it?

First step – always be suspicious. If the mail you are receiving was not expected or does not look quite right (spelling mistakes are a dead giveaway), the chances are that it is spam.

Second step – click nothing! Until you are certain the email is genuine, don’t even think about following a link. Just drift your pointer over a link and wait a moment – the address to which it links will magically appear!

ExtraMile is focused on information security, earning us the ISO 27001. Read more.

The link in the mail above – supposedly from Barclays – is actually linking to a website that you are unlikely to know. You can be certain that clicking this link will not be to your benefit.

Third step – not all mails have a link. Some emails will enclose an attachment. This might be an html document or a zip file (a compressed file). Opening these is likely to be harmful to your machine – open no attachment unless you are certain of its source. Would you feel safe if you were asked to phone a number? Best not do it unless you are sure – it may be a premium line. Another very clever trick!

Fourth step – be careful about unsubscribe links. Again, if you don’t know the sender or the email looks suspicious or any of the above elements has taken place, then don’t click the unsubscribe link. The chances are that this will simply load an unwanted website or may perform the same job as the main link in the mail.

Fifth step – don’t open images. If your email software doesn’t open the email’s images automatically, then don’t opt to load them if you are suspicious. The reason? When images open on your computer, the sender knows that you have received the email. That means that yours is a live address – therefore it’s valuable. By the same token, don’t reply to these emails. Sometimes that is hard to avoid – particularly if you put an auto-response on your emails because you are out of the office for example.

Sixth step – mark it as junk/spam. If you have a junk mail filter on your email system, use it. It may help you to reduce the amount of unwanted email that actually makes it to your inbox. Instead it is routed to the Junk folder where you can peruse it at your leisure, in quarantine. Then, you can delete it.

So what will happen ultimately?
The names of banks, online retailers, PayPal, eBay, social media and many others are used illicitly to lure people with false messages. Many of these organisations are taking steps to eradicate the misuse of their brand, but spammers move quickly and cover their tracks. Recent efforts, particularly by the US government, to close down spam networks have met with a certain amount of success, but spam email, like junk postal mail, is likely to be with us for a long long time.

If you want to know more about spam and its impact, the Securelist reports are a useful source of information.